Available at: http://digitalcommons.calpoly.edu/theses/212
Date of Award
MS in Electrical Engineering
The DI water is commonly used to rinse production wafers to remove mechanical and chemical residue without any problematic chemical reaction in rinse process. The semiconductor industry wants to save their manufacture cost and reduce the industrial residue by recycling the deionized water during CPM process. The conductivity in recycled DI water is integrated over the time period.
The Drain Diverter, deionized wafer filtering system, is the automated system that detects the level of ions and controls the drain system by using conductive probes. The system contains hysteresis loop, valve feedback, relay circuit, and facility interlock. The recycled water valve is immediately closed when the contaminated water is detected by the conductive probes.
The Drain diverter is the project designed for the semiconductor equipments company, and is currently integrated and operating in semiconductor manufacture facility of a chip maker, filtering contaminated DI water from the chamber. And the time delay of the recycled water valve responses is 140mSec for 60PSI of flow pressure.